Coronary heart disease (CHD) is a major cause of death and disability in Ireland. In many cases, there are no signs or symptoms. A sudden, sometimes fatal heart attack may be the first sign that anything is wrong. For this reason, it can be difficult to persuade people to make the simple lifestyle changes that can protect heart health, despite many Government and charity-funded campaigns.

As a result of robust research and clinical trials there has been extensive media coverage of the heart health benefits associated with the omega-3 long-chain polyunsaturated fatty acids (LCPUFA). LCPUFA are the type that are found in foods of marine origin like oily fish and fish oil supplements. These omega-3’s are also recognised as heart protective by medical and Government advice.

Fish oil supplements offer an attractive natural source of these valuable nutrients for those people whom, for whatever reason, do not eat sufficient oily fish.

Heart Disease - Ireland’s No.1 killer

Approximately 10,000 people die each year from cardiovascular disease (CVD) - including coronary heart disease (CHD), stroke and other circulatory diseases. CVD is the most common cause of death in Ireland, accounting for 36% of all deaths. The largest number of these deaths relate to CHD - mainly heart attack. Approximately 2,000 people die from stroke each year accounting for more deaths than breast cancer, lung cancer and bowel cancer combined. Up to 10,000 people suffer stroke annually and there are an estimated 30,000 people in the community with residual disability from stroke. (Source: Irish Heart Foundation)
 

Background to Omega-3 fatty acids

The association between omega-3 polyunsaturated fatty acids and heart health was made in the 1970s by scientists who noted that heart disease was virtually non-existent among the Greenland Inuits despite their high fat diet of blubber and oily fish. They concluded that it was the type of fat they ate that made the difference. Many studies since have confirmed this thinking, (notably the DART intervention trial in the UK, the GISSI study in Italy and the Singh trial in Asia). The omega-3’s are one of the two essential fatty acid (EFA) families vital to life and to health. Like all fats, they provide energy. In fact, as their EFA description suggests, they are essential and must be consumed regularly as the body has limited storage for them. Experts think that man evolved on a diet which would have had roughly 1-2 times more omega-6 than omega-3. Currently, western diets are in a ratio of around 10:1 in favour of the omega-6’s. Because of their wide ranging roles, virtually every area of the human body is susceptible to problems if the balance of omega-6 and omega-3 becomes out of kilter. How extreme the imbalance needs to be before problems are felt is not yet known. Although it is well established that the omega-3 derived from fish are heart protective, there is still some discussion about exactly how they work. They are known to be:

• anti-arrhythmic and anti-inflammatory
• reduce platelet aggregation (blood clots)
• stabilise atherosclerotic plaques
• lower blood triglycerides
• improve arterial elasticity

Heart Disease

The heart is a muscular pump that sends blood around the body to supply it with oxygen and vital nutrients. First the blood travels to the lungs to collect oxygen and then returns to the heart before being circulated round the body through the arteries before returning to the heart via the veins. Then the cycle starts all over again. The primary cause of heart disease is a process called atherosclerosis - the formation of fatty deposits (plaques or atheroma) under the lining of a coronary artery, effectively narrowing its circumference. When this happens, blood supply to the heart muscle is restricted, starving it of oxygen. Angina and increased risk of heart attack are the result.

Angina
• Angina (Angina Pertoris) is recurring pain or discomfort in the chest. It is a discomfort you experience when your heart cannot get enough blood. The discomfort does not damage your heart but is a warning symptom that there is a problem with the blood supply to your heart. Angina feels like a pressing or squeezing pain, usually in the chest under the breastbone, but sometimes in the shoulders, arms, neck, jaws, or back. Physical exertion is the most common trigger. Other triggers can be emotional stress, extreme cold or heat, heavy meals, alcohol and cigarette smoking.

Heart Attack
• A heart attack happens when the blood supply to a part of the heart muscle is interrupted or stops - usually because a blood clot (thrombus) in an artery already narrowed by atherosclerosis, blocks the flow of blood (and oxygen) to a section of the heart. If one of the main coronary arteries is blocked, a large part of the heart muscle is affected. Clotting is the body’s natural response to injury. Without it, we would bleed to death. Severe chest pain is the usual symptom of a heart attack. It can be severe or may be mistaken for indigestion. The pain may travel up to the jaw and down the left, or both, arms. Other symptoms include sweating, light headedness, breathlessness or nausea. A heart attack is not always fatal but in people who survive a heart attack the part of the heart muscle that dies is replaced by scar tissue over the next few weeks.

Who’s at risk?

Some heart disease risk factors are associated with genetic inheritance and age, and therefore cannot be changed. These Include
• Gender – deaths from heart disease are higher in men than women
• Age – most people over the age of 40 have some noticeable plaque build up in their arteries
• Family history – people are at a greater risk if a member of their immediate family suffered from coronary heart disease before they were 60 years old

Reducing the risk

Other CHD risk factors can be modified by lifestyle changes and medication:

1. Poor diet
• An unhealthy diet is a major risk factor for coronary heart disease. Diet can have both a negative and positive effect on heart health. There are certain foods and micronutrients in food that are good for the heart and others that are harmful:

Eat less
- Salt – on the table and in cooking
- Saturated fat
- Full fat dairy products like cheese, milk and cream
- Vegetable oils and margarines containing omega-6
- Pre-prepared and processed foods
- Foods fried at high temperatures

Eat more
- Fruit and vegetables that contain antioxidant nutrients like vitamins A, C and E.
- Fibre has been shown to help reduce blood cholesterol levels.
- Oily fish (e.g. mackerel, sardines, herring, pilchards and salmon) that contain the long-chain omega-3 fatty acids that protect heart health in many ways.
- For people who, for whatever reason, choose not to eat at least one oily fish meal a week, fish oil supplements are available.

2. High LDL blood cholesterol and tryglyceryde levels
• Cholesterol is a fatty substance that is found naturally in the bloodstream and in all body cells. Only a small proportion of the body’s cholesterol comes from cholesterol in food. Most is made in the liver from saturated fat found in food. Low-density lipoprotein (LDL) is the main cholesterol carrier in the blood. A high level of LDL cholesterol may reflect an increased risk of CHD. Elevated cholesterol and triglyceride levels can be modified by diet, mainly by the reduction of saturated fats.

3. Smoking
• Each year, smoking accounts for approximately 20% of all heart disease deaths. Pharmacies are well placed to advise and offer advice regarding nicotine replacement therapy. Information on quitting is available from The National Smokers Quitline 1850 201 203.

4. High Blood Pressure (Hypertension)
• The heart must work harder to pump blood through narrowed arteries and over time the increased pressure causes damage to the heart and blood vessels. Often called the “silent killer,” hypertension usually causes no symptoms until it reaches a life threatening stage. All adults should have their blood pressure checked at least once every five years but preferably more often for older age groups as blood pressure rises with age. Blood pressure on the high side of normal (between 130/85 and 139/89 mmHg) should be checked every year. Medication may be prescribed, but diet and lifestyle changes can make a difference. The most important dietary change is salt reduction.

5. Sedentary lifestyle
• Exercise helps lower blood sugar and blood pressure, makes arteries more flexible and less prone to hardening and helps weight control. Lifelong regular exercise is one of the cornerstones of heart health maintenance. People with high blood pressure or pre-existing heart disease should consult their doctor before embarking on an exercise programme.

6. Obesity
• Obesity is most commonly defined in terms of body mass index (BMI), which is calculated by dividing your weight in kilograms by the square of your height in meters (BMI=kg/m2), A desirable BMI is considered to be in the region of 20 to 25. Above this is defined as ‘overweight’ and a BMI over 30 is defined as ‘obese’. Being seriously overweight hastens the onset of heart disease by an average of seven years.

7. Diabetes
• Diabetes appears to increase heart disease risk. It is thought that higher than normal blood glucose levels affect the lining of arterial walls, which in turn can increase susceptibility to atherosclerosis. In Ireland, it is estimated that there are 200,000 people with diabetes with many unaware. Modern treatment of diabetes can protect against atherosclerosis, so early diagnosis is important.

8. Excess Alcohol
• Drinking alcohol above recommended limits is likely to raise blood pressure. Advice is simply to drink no more than two (women) or three (men) units a day and never binge drink.

9. Stress
• Evidence supporting a link between stress and heart disease is not strong, but individual response to stress may be a contributing factor. Some scientists have noted a relationship between CHD risk and stress.

Health protective benefits of Omega-3

The omega-3 fatty acids are a family of polyunsaturated fatty acids essential to life. They cannot be made in the body so must be obtained from diet. However, the typical Irish diet now supplies omega-3 levels well below what the body needs for good health. The evidence linking consumption of omega-3 with reduction of risk of heart disease and heart attack death is so convincing that the government recommends that people increase the amount of oily fish in their diet. Oily fish like mackerel, herring and sardines are the only good dietary source of the long-chain omega-3. For people who prefer not to eat oily fish, fish oil supplements provide an excellent alternative. Remember that white fish like cod are not oily fish and that convenience fish products (e.g. fish fingers) may not be of any real benefit.

Oily fish versus fish oil supplements

In an ideal world, everyone should be able to obtain the omega-3 nutrients they need from diet by eating at least two fish meals a week. In practice, however, this simply isn’t happening despite encouragement from dietitians and nutritionists. Some people do not like the taste or the smell, others find the bones a problem and yet others find shopping, storing and cooking fish an inconvenience.

As an alternative, fish oil supplements offer the following benefits:
• Convenience: widely available, portable and easy to store over long periods without spoiling. Easy to take any time, anywhere.
• Measurable dose and dosage options: liquid or capsules in a choice of strengths.
• Refined: the refining process removes environmental pollutants like PCBs and dioxins.

The omega-3 fatty acids

Are thought to protect the heart in many ways: